If he likens it to schism, then he really does not understand it.
Sede clergy refuse the sacraments to r&r people, and tell sedes they will commit a mortal sin if they go to r&r clergy for the Mass and sacraments.
Yet all the while, at the same time
the same sede clergy still claim these r&r clergy are still “catholic”.
So they are refusing the sacraments to people they consider Catholic, and forbidding other Catholics from receiving go the sacraments from clergy they somehow still regard as Catholic.
This is flat out schism.
“The sin of schism is also committed by separation from the members of the Church. Thus, one who refuses to communicate with Catholics in matters of faith or worship, choosing to act as an independent in those things, is a schismatic.”